In 1983 I published a draft of an introduction to this book. Contrary to my intention then, I shall not repeat what I wrote there, merely refer to it. Only a few points necessary for the understanding of this period of church history will be set out here by way of a prelude.

He who concerns himself with church history must be constantly aware of the fact that it is a whole of which all isolated happenings are merely a part; for it is determined by divine foreknowledge. However puzzling may be the connections between its transcendental origins and destination on the one hand and its human, sometimes all too human course on the other, this unity is nowadays seen as a crucial element of church history by church historians of all confessions, whatever they may understand by the term church history. Even an author like Joseph Lortz regarded it as fruitless ‘to acknowledge the existence of certain questionable episodes in church history and the history of theology’. It would be to diminish God's control over history if one were small-mindedly to try to explain away its many weaknesses, scandals, and contradictions; God rules the world and makes human error a tool of his will – even human guilt is made use of in this way and becomes felix culpa.

Such a conception allows full freedom to a scholarly study of church history. Nothing need be touched up or passed over in an apologetic spirit. The history of the church needs no human advocate.